G-SYNC 101: Control Panel


G-SYNC Module

The G-SYNC module is a small chip that replaces the display’s standard internal scaler, and contains enough onboard memory to hold and process a single frame at a time.

The module exploits the vertical blanking interval (the span between the previous and next frame scan) to manipulate the display’s internal timings; performing G2G (gray to gray) overdrive calculations to prevent ghosting, and synchronizing the display’s refresh rate to the GPU’s render rate to eliminate tearing, along with the delayed frame delivery and adjoining stutter caused by traditional syncing methods.

G-SYNC Demo

The below Blur Busters Test UFO motion test pattern uses motion interpolation techniques to simulate the seamless framerate transitions G-SYNC provides within the refresh rate, when directly compared to standalone V-SYNC.

G-SYNC Activation

“Enable for full screen mode” (exclusive fullscreen functionality only) will automatically engage when a supported display is connected to the GPU. If G-SYNC behavior is suspect or non-functioning, untick the “Enable G-SYNC, G-SYNC Compatible” box, apply, re-tick, and apply.

Blur Buster's G-SYNC 101: Control Panel

G-SYNC Windowed Mode

“Enable for windowed and full screen mode” allows G-SYNC support for windowed and borderless windowed mode. This option was introduced in a 2015 driver update, and by manipulating the DWM (Desktop Windows Manager) framebuffer, enables G-SYNC’s VRR (variable refresh rate) to synchronize to the focused window’s render rate; unfocused windows remain at the desktop’s fixed refresh rate until focused on.

G-SYNC only functions on one window at a time, and thus any unfocused window that contains moving content will appear to stutter or slow down, a reason why a variety of non-gaming applications (popular web browsers among them) include predefined Nvidia profiles that disable G-SYNC support.

Note: this setting may require a game or system restart after application; the “G-SYNC Indicator” (Nvidia Control Panel > Display > G-SYNC Indicator) can be enabled to verify it is working as intended.

G-SYNC Preferred Refresh Rate

“Highest available” automatically engages when G-SYNC is enabled, and overrides the in-game refresh rate selector (if present), defaulting to the highest supported refresh rate of the display. This is useful for games that don’t include a selector, and ensures the display’s native refresh rate is utilized.

“Application-controlled” adheres to the desktop’s current refresh rate, or defers control to games that contain a refresh rate selector.

Note: this setting only applies to games being run in exclusive fullscreen mode. For games being run in borderless or windowed mode, the desktop dictates the refresh rate.

G-SYNC & V-SYNC

G-SYNC (GPU Synchronization) works on the same principle as double buffer V-SYNC; buffer A begins to render frame A, and upon completion, scans it to the display. Meanwhile, as buffer A finishes scanning its first frame, buffer B begins to render frame B, and upon completion, scans it to the display, repeat.

The primary difference between G-SYNC and V-SYNC is the method in which rendered frames are synchronized. With V-SYNC, the GPU’s render rate is synchronized to the fixed refresh rate of the display. With G-SYNC, the display’s VRR (variable refresh rate) is synchronized to the GPU’s render rate.

Upon its release, G-SYNC’s ability to fall back on fixed refresh rate V-SYNC behavior when exceeding the maximum refresh rate of the display was built-in and non-optional. A 2015 driver update later exposed the option.

This update led to recurring confusion, creating a misconception that G-SYNC and V-SYNC are entirely separate options. However, with G-SYNC enabled, the “Vertical sync” option in the control panel no longer acts as V-SYNC, and actually dictates whether, one, the G-SYNC module compensates for frametime variances output by the system (which prevents tearing at all times. G-SYNC + V-SYNC “Off” disables this behavior; see G-SYNC 101: Range), and two, whether G-SYNC falls back on fixed refresh rate V-SYNC behavior; if V-SYNC is “On,” G-SYNC will revert to V-SYNC behavior above its range, if V-SYNC is “Off,” G-SYNC will disable above its range, and tearing will begin display wide.

Within its range, G-SYNC is the only syncing method active, no matter the V-SYNC “On” or “Off” setting.

Currently, when G-SYNC is enabled, the control panel’s “Vertical sync” entry is automatically engaged to “Use the 3D application setting,” which defers V-SYNC fallback behavior and frametime compensation control to the in-game V-SYNC option. This can be manually overridden by changing the “Vertical sync” entry in the control panel to “Off,” “On,” or “Fast.”



3006 Comments For “G-SYNC 101”

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dandyjr
Member
dandyjr

Hey Jorimt, I have a question regarding the issue of avoiding the G-Sync ceiling.

I recently purchased a 280Hz Freesync monitor (it’s not official G-Sync Compatible but after testing in multiple games, it seems to mirror my 144Hz officially G-Sync Compatible monitor in accuracy) and I’ve noticed an issue that has happened on previous monitors I’ve owned as well.

This monitor doesn’t have an OSD that I can have toggled on at all times so I had to manually open the menu to check each time but I’ve noticed that there are multiple moments where the refresh rate will read as 280Hz instead of whatever framerate the game is reading as at the time.

For example, I tried with in-game and external limiters, I can cap the frames at 240fps and the game will read as 240fps but when I open the menu of the monitor, it reads as 280Hz for that moment (causing me to believe that G-Sync has disabled in that moment and Vsync has toggled on). Then I’ll close the menu and reopen it and then the refresh rate will read as some variation under the 280Hz ceiling. That lets me know that G-Sync does engage, but there are moments where it’s not engaging even when it should.

I tested this in multiple games with multiple forms of framerate caps and noticed the same trend. The closer I capped to 280Hz, the more times I would see 280Hz in the monitor. The only way to stop it from happening was to cap the framerate far below the ceiling. Capping at 277fps, for example, in RTSS caused the 280Hz readout to never change at all (which would indicate that G-Sync was not engaging) which caused me a lot of frustration.

I would think that it’s possibly due to the monitor not being offically G-Sync Compatible but the same issue would happen with my 144Hz monitor as well (with lower framerates of course because the ceiling is lower) and that monitor had an OSD that I could leave toggled on. I would see the numbers rapidly change and by watching very closely, you could see the 144Hz flash multiple times within the mixture.

Am I overthinking this or are the monitors actually reading correctly and G-Sync is disengaging and re-engaging constantly even with framerate caps below the ceiling?

It’s sad to think that the 280Hz ceiling is useless because framerates need to be capped far below the ceiling even with external limiters that appear to be perfect in execution.

TkoSeven
Member
TkoSeven

Thanks for the wonderful article.

2 questions!

Adjust desktop size and position section,
“Perform scaling on: Display or GPU” (also override the scaling mode set by games and programs)
does it matter in terms of how g-sync monitor
interacts with GPU?

2nd question on “Max frame rate” on Nvidia settings,
if a game was designed to be locked at 60fps, like Tekken 8,
Nvidia panel set to 58 fps, does it work by limiting frame data transferred to display even though
the logic of the game (application) actually went through generating data for 60 frames?
or
does it actually limit the game to only generate 58 frames?

thank you in advance.

eeayree
Member
eeayree

Hi jorimt. I myself am from another country and therefore I hope that the translator will do his job correctly. Now I’m playing Metro 2033 and this game can produce from 80 to 120 fps on my system and at the same time the GPU is not working at full capacity. It works within 85 percent. Your tuning guide states that it is best to enable low latency mode in cases where the frame rate does not always reach or exceed the refresh rate. Am I doing the right thing if I leave low latency mode on if the video card is not loading at 99%? And at what percentage values ​​does the delay appear exclusively at 99%? On 95, 96, 97 will everything work with minimal delays?

SovonHalder
Member
SovonHalder

HI jorimt, I can’t thank you enough for writing this article. I read pages 1 through 15 multiple times to understand as much as I cound and i’t’s incredibly useful for folks like me who are new to PC gaming. Just wanted to acknowledge that adn say many thanks brother.

So I set up things for my 144hz 32GR93U exactly as you described: In nvcp Gsync+Vsync+Low latency ultra and the in game Vsync, double or triple buffering off and fullscreen on. I have 2 questions basically.

1. In most games I’ve tried so far like alan wake 2, god of war, stray the fps is capped automatically to 138 as it should but in red dead online (vulkan) it maxes out at 144. I use rtss to set it custom 138 but the question remains. Why doesn’t it happen automatically?

2. The new nvidia app reports an Average PC Latency in their overlay. For me above 60ms with mouse and controller feels sluggish whereas when it’s below 30ms the game feels much more responsive. I want to implement that on my RTSS stat overlay. (I find rtss overlay more robust and feature rich and I can see frametime grap and nvidia overlay is finicky and slow.) Could you share some insight as to how they are calculating that number?

Ezi
Member
Ezi

I have a question, so i did the settings you suggested and my gpu usage went from 99% usage to hovering around 70-88ish. Is this normal? Cause if i were to default everything back, the usage would go back to 99%

these are the settings i have in NCP:
– vsync on in NCP, off ingame
– set fps limiter -3
– gsync enabled – full screen
– LLM set to ultra since ingame doesnt have a limiter

my pc spec is:
– 4080 super FE
– 7800x3D
– M32U 4k 144hz monitor

wpDiscuz